1. Field of the Invention
The present invention relates to a fuse data read circuit.
2. Description of Related Art
With advancement of semiconductor technologies, there has been known a technique for expanding the storage capacity of a semiconductor storage by increasing the number of storage elements incorporated in the semiconductor storage. In some cases, storage elements incorporated in a semiconductor memory device may include a storage element that does not operate properly (hereinafter referred to as a bad memory cell).
If a proportion of the bad memory cells to the entire storage elements is high, then the yield of the semiconductor memory devices decreases. A technique for preventing a reduction in the yield has been known in which redundant memory cells (hereinafter referred to as spare memory cells) are provided in a predetermined area in a semiconductor storage and are used to replace the bad memory cells (refer to Patent Document 1, for example).
When bad memory cells are replaced with spare memory cells, the addresses of the bad memory cells are stored in fuses. A semiconductor storage causes the fuses to store the addresses of the bad memory cells to be replaced with the spare memory cells, by turning ON (not disconnecting)/OFF (disconnecting) redundancy fuses in the fuse window. The semiconductor storage built in an electronic device replaces the bad memory cells with the spare memory cells and performs read/write operations, when power of the electronic device is turned on.
(Patent Document 1) Japanese Patent Application Laid Open No. 2000-200497